Waterproof watchcase



y 1951 E. K. SCHWAIBOLD 2,553,012

WATERPROOF WATCHCASE Filed Oct. 15, 1948 INVENTOR. [020/ /f. Qfv/flzaa/la/d Patented May 15, 195-1 WATERPROOF WATCHCASE Edgar K. Schwaibold, Ludington, Mich, assignor to Star Watch Case Company, Ludington,

Mich.

Application October 15, 1948, Serial No. 54,797

Claims. 1

This invention relates to improvements in waterproof watch'case.

The principal objects of this invention are:

First, to provide a watch case particularly of the strap typewhich is highly resistant to corrosion and waterproof.

Second, to provide a gold plated watch case with a corrosion proof connection between the bezel and the back.

Third, to provide a connection between the back and bezel of a watch case which permits the use of r latively inexpensive gold filled material for the bezel. y

Other objects and advantages pertaining to details of the watch case will be apparent from a consideration of the following description and claims.

The drawings of which there'is one sheet illustrate two formsof my watchcase.

Fig. l is an elevational view, partially broken away in cross-section, of a watch case embodying my invention.

Fig. 2 is an enlarged fragmentary cross-sectional view illustrating in detail the connection between the back and bezel of the watch.

Fig. 3 is an enlarged fragmentary cross-sectional view of a modified form of watch case.

Waterproof watch cases are usually of the strap or wrist type where the back of the watch is constantly exposed to perspiration from the wearers wrist. One of the possible places of entry of moisture into the case is through the threaded connection between the bezel and the back of the case and it is therefore necessary to provide an accurate tight fitting connection at that point. So long as the back and bezel are made entirely of corrosion resistant materials such as solid gold this tight threaded connection is relatively easy to maintain. However when a less expensive gold rolled or gold filled bezel is used the cutting of the threads in the bezel exposes the base metal at the back of the case to the corrosive action of the perspiration and the connection will eventually corrode sufiiciently to permit moisture to enter the case. My construction permits the use of relatively inexpensive gold rolled or gold filled bezels and still avoids the corrosion at the connection between the back and the bezel.

In Figs. 1 and 2 I have illustrated a strap watch having a bezel I, a crystal 2 and back 3. The bezel is provided with the usual ears 4 for attachment of a strap and a stem 5 for Winding the movement or the watch. The rear side of the bezel l is provided with an annular insert 6, the

inside of which is machined to provide the threads I for engaging the mating thread on the back 3. As is shown in greater detail in Fig. 2 the bezel l is provided with a relatively thin outer coating 3 of gold or otherprecious metal to enhance the appearance of the watch and render it noncorrosive. The back of the bezel is shouldered as at 9 to receive the forward face of the insert 6 which is secured to the bezel as by a suitable brazing operation. The insert 6 is made of stainless steel orother non-corrosive material and projects rearwardly from the rear face of the bezel so that the rear of the coating 8 does not contact the wearerswrist.

The back 3 is also made of stainless steel or other non-corrosive material and the threads I can be accurately formed to provide a water tight joint. Since the threads themselves are formed in non-corrosive metal there is little tendency-for the threaded joint to erode and permit moisture to enter the case.

Fig. 3 illustrates a modified form of the case in which the bezel iii is provided with a rearwardly extending curved surface H. The insert i2 is radially thinner than the insert 6 but is secured within a shoulder I3 in the bezel substantially the same as in the first form of the case. The insert I2 is provided with the internal threads [4 mating with threads formed around the back l5 and both the insert and the back are formed of corrosion resistant material. The brazed connection between the insert and the bezel indicated at i6 prevents erosion of the base metal in the bezel and the threaded connection between the insert and back is corrosion proof as in the first form of the case.

The construction shown in Fig. 2 is of particular advantage that very little of the rear surface of the bezel is exposed and less work is required to form the gold rolled surface 8 on the bezel than would be the case if the entire bezel had to be coated.

It will be appreciated that the particular shape of the various parts are examples only and can be varied to suit the artistic taste of different persons.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

l. A watch case comprising, an annular bezel of base metal having an internal shoulder spaced forwardly of the rear side there, said shoulder having substantially greater width than depth,

a coating of precious metal on the outer surface of the said bezel and extending to the edge of said shoulder, an annular insert of corrosion resistant metal seated against said shoulder and secured thereto, said insert abutting against said coating completely around said insert and having an internal thread spaced radially from said coating and extending forwardly from its rear edge, and a back member of corrosion resistant material having an external thread formed around its periphery and mating with said internal thread.

2. A watch case comprising, an annular bezel of base metal having an internal shoulder spaced forwardly of the rear side thereof, a coating of precious metal on the outer surface of the said bezel and extending to the edge of said shoulder, an annular insert of corrosion resistant metal seated against said shoulder and secured thereto, said insert abutting against said coating completely around said insert and having an internal thread spaced radially from said coating and extending forwardly from its rear edge, and a back member of corrosion resistant material having an external thread formed around its periphery and mating with said internal thread.

3. A watch case comprising an annular bezel of base metal having a recessed shoulder in the rear side thereof, a coating of precious metal on the outer surface of the said bezel and extending to the edge of said shoulder, a cylindrical insert of corrosion resistant metal seated against said shoulder and secured thereto, said insert abutting against said coating completely around said insert and having an internal thread spaced radially from said coating and extending forwardly from its rear edge, and a back member of corrosion resistant material having an external thread formed around its periphery and mating with said internal thread.

4. A watch case comprising an annular bezel of base metal having a recessed shoulder in the rear side thereof, a coating of precious metal on the outer surface of the said bezel and extending to the edge of 'said shoulder, a cylindrical insert of corrosion resistant metal seated against said shoulder and forming a continuation of the rear surface of said bezel, said insert abutting against said coating completely around said insert and having an internal thread spaced radially from said coating and extending forwardly from its rear edge, and a back member of corrosion resistant material having an external thread formed around its periphery and mating with said internal thread.

5. A watch case comprising, an annular bezel of base metal having a recessed shoulder in the rear side thereof, a coating of precious metal on the outer surface of the said bezel and extending to the edge of said shoulder, an annular insert of corrosion resistant metal seated against said shoulder, said insert abutting said coating completely around said insert and having an internal thread spaced radially from said coating and extending forwardly from its rear edge, and a back I member of corrosion resistant material having an external thread formed around its periphery and mating with said internal thread.

EDGAR K. SCHWAIBOLD.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS 

